#include <cstdio>
#include <cstring>
#include <iostream>
#include <algorithm>
using namespace std;
const int maxn = 1e5+10;
int a[maxn];
int main()
{
	int t;
	scanf("%d",&t);
	while(t--)
	{
		int n;
		scanf("%d",&n);
		for(int i = 1;i<=n;i++) scanf("%d",&a[i]);
		a[0] = 0;
		int lcnt = 0;
		int flag = 0;
		int maxl = 0;
		for(int i=2;i<=n;i++)
		{
			if(a[i]==a[i-1]+a[i-2])
			{
				if(!flag) 
				{
					//printf("***\n");
					if(i==2) lcnt = 2;
					else lcnt = 3;
					flag = 1;
				}
				else lcnt++;
			}
			else 
			{
			
				flag = 0;
			}
			if(lcnt>maxl) maxl = lcnt;
		}
		printf("%d\n",maxl);
	}
}
